This invention relates to drilling guides and more particularly to doweling jigs that facilitate the generation of accurately drilled dowel receiving holes in wood workpieces which are to be joined in abutting edge-to-edge, edge-to-end and edge-to-inside of surface joinery operations.
U.S. Pat. No. 2,602,238 to Wellman and the improved U.S. Pat. No. 5,782,006 to Erway, et al demonstrate centering jigs that are capable of moving two opposing clamp jaws simultaneously. The drill guide member is centrally located to drill through the center of the workpiece. These two jigs function satisfactorily if the two workpieces being joined are of exactly the same thickness. For edge-to-edge assembly sequences, any variations in thickness of the adjoining workpieces will cause a step at the joint which requires sanding to bring the joining pieces flush. Also, these centering jigs do not accommodate the edge-to-surface joint operation. Furthermore, the drill guide member provides several different bore sizes that limit the user to drill only one hole at a time.
The doweling jigs made by Dowel-it Co. allow the user to select drill bushings for the particular dowel operations, but the hole into which the bushing is screwed cannot be used for the drill guide because those holes are not standard sizes. Internally threaded bores which receive the interchangeable bushings are not usable as drilling guides.
In U.S. Pat. No. 5,407,307 to Park, the doweling jig facilitates the generation of accurately drilled, dowel receiving holes in workpieces which are to be joined in abutting, edge-to-edge, or edge-to-surface joints. Since this doweling jig has drill guide bushings that are permanently located in the clamping assemblies, it has limited hole size capability. Moreover, securing the clamping assemblies for the edge-to-surface operation is not user-friendly because of the lack of holding means during use.
There is need for a doweling jig which permits drilling dowel holes which are positioned so that, when two pieces of wood are edge-joined, one surface is even to reduce sanding.
There is also need for a doweling jig which can clamp two pieces of wood together so that the companion dowel holes are drilled at the same time.
There is also need for a doweling jig which is capable of application in different ways, such as selectively drilling companion dowel holes the same distance from the surface on two different boards to be edge-glued or centering them in those boards. It is desirable for the doweling jig to be sufficiently versatile to also permit the drilling of dowel holes in an edge-to-end holes in one board and companion side surface holes at the end of or intermediate the ends of another board. Thus, there is need for a versatile doweling jig.
In order to aid in the understanding of this invention, it can be stated in essentially summary form that it is directed to a woodworking doweling jig. The doweling jig includes two clamp members for clamping together two planks. The guide rods permit sliding clamping motion between the two clamp members. At least one drill guide, and preferably two, are mounted between the clamp members. The drill guides have dowel drill holes therein which are aligned in the direction of the guide rods. The dowel drill holes preferably have interchangeable bushings. An alignment member is mounted either separately or integrally with the top clamp member. The alignment member has guide slots therein in alignment with the drill guide holes for assuring the alignment of edge-mounted dowel holes with surface-drilled dowel holes.
It is a purpose and advantage of this invention to provide a doweling jig that provides accurate drilling guides for the drilling of dowel-receiving holes for (1) edge-to-edge, (2) edge-to-end of surface, and (3) edge-to-inside of surface operations in one tool.
It is another purpose and advantage of this invention to provide a doweling jig that is easy to use, requires minimal or no set-up, is quick in application, yields accurately placed drill guide center locations for all three major doweling operations, and yields flush workpiece surfaces after the final doweling and assembly sequences are completed.
It is another purpose and advantage of this invention to provide a doweling jig which has self-centering and flush surface joint capabilities in one tool.
It is another purpose and advantage of this invention to provide a doweling jig that allows the user to select the distance from the center of the hole to the surface of the workpiece.
It is another purpose and advantage of this invention to provide a doweling jig that can clamp two workpieces for drilling during one clamping operation for edge-to-edge operations.
It is another purpose and advantage of this invention to provide a doweling jig that has a separable alignment block for edge-to-surface operations.
It is another purpose and advantage of this invention to provide a doweling jig that provides two functions for bored holes to accommodate interchangeable bushings. The drill guide bore is configured not only to be used for a drilling guide but also to be able to carry interchangeable bushings to achieve any reduced size drilling.
It is another purpose and advantage of this invention to provide a doweling jig which also has V-grooves on the clamping surfaces to drill holes axially in the center of round workpieces.